From 4f08c85c69a3e0ae056aba3fe8ab2d289597edcd Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 2 Nov 2016 12:41:00 +0100
Subject: [PATCH] hydra-queue-runner: Fix assertion failure

It was hitting

    assert(reservation.unique());

Since we do want the machine reservation to be released before calling
wakeDispatcher(), let's use a different object for keeping track of
active steps.
---
 src/hydra-queue-runner/builder.cc | 11 ++++++-----
 src/hydra-queue-runner/state.hh   | 10 +++++++---
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/hydra-queue-runner/builder.cc b/src/hydra-queue-runner/builder.cc
index 9f01425d..b0e96e95 100644
--- a/src/hydra-queue-runner/builder.cc
+++ b/src/hydra-queue-runner/builder.cc
@@ -13,13 +13,14 @@ void State::builder(MachineReservation::ptr reservation)
 
     nrStepsStarted++;
 
-    reservation->threadId = pthread_self();
-
-    activeSteps_.lock()->insert(reservation);
+    auto activeStep = std::make_shared<ActiveStep>();
+    activeStep->step = reservation->step;
+    activeStep->threadId = pthread_self();
+    activeSteps_.lock()->insert(activeStep);
 
     Finally removeActiveStep([&]() {
-        reservation->threadId = -1;
-        activeSteps_.lock()->erase(reservation);
+        activeStep->threadId = -1;
+        activeSteps_.lock()->erase(activeStep);
     });
 
     auto step = reservation->step;
diff --git a/src/hydra-queue-runner/state.hh b/src/hydra-queue-runner/state.hh
index 31898d01..7de2af86 100644
--- a/src/hydra-queue-runner/state.hh
+++ b/src/hydra-queue-runner/state.hh
@@ -370,13 +370,17 @@ private:
         State & state;
         Step::ptr step;
         Machine::ptr machine;
-        pthread_t threadId = 0;
-        bool cancelled = false;
         MachineReservation(State & state, Step::ptr step, Machine::ptr machine);
         ~MachineReservation();
     };
 
-    nix::Sync<std::set<std::shared_ptr<MachineReservation>>> activeSteps_;
+    struct ActiveStep
+    {
+        Step::ptr step;
+        pthread_t threadId;
+    };
+
+    nix::Sync<std::set<std::shared_ptr<ActiveStep>>> activeSteps_;
 
     std::atomic<time_t> lastDispatcherCheck{0};